The present invention relates to a pH control system for the alkaline waters from the ready-mix concrete batching process.
Stormwater permitting has been required of concrete plants since 1992, under revisions to the Clean Water Act. Additional requirements have been implemented by local and state governments under their respective NPDES (National Pollutants Discharge Permit) permits. Under these requirements, industrial activities that have stormwater discharges, with pollutants associated with the industrial activities, must meet certain minimum levels of treatment for pollutants specifically identified in their permit. As set by the U.S. Environmental Protection Agency (EPA), the concrete industry is required to minimize or eliminate to the maximum extent possible sand and fine materials, cementatious materials, pH levels higher than 9.0, admixtures, oils and greases.
Typical systems for treating plant waste water are bulky and expensive to manufacture and operate. These systems typically utilize a much stronger acid (sulfuric acid), which can cause permanent damage to the equipment operator if it comes into contact with the skin or eyes. Additionally, spills require specialized clean up procedures requiring assistance from an experienced hazardous waste contractor or public response crew.